Steam generator



Dec. 17, 1929. T, CULLEN, ,JR 1,740,337

STEAM GENERATOR Filed Aug. 4, 1928 2 Sheets-Sheet 1 Dec. 17, 1929. T, CULLEN, JR 1,740,337

STEAM GENERATOR Filed Aug. 4. 1928 2 Sheets-Sheet 2 Patented Dec.. 17, 1929 V i i UNITED STATES PATENT OFFICE JOHN T. CULLEN, JR, F CLINTON, IOWA s'rnAM GENERATOR Application filed August 4, 1928. Serial No. 297,486.

This invention relates to a steam generator, welded, riveted, or otherwise suitably conone of the objects being to provide a device nected water-legs 4 and 5 which open into of this character which can be produced at the space between the shell 1 and the inner the minimum cost and will afford a large shell 6. The sides of this inner shell are I 5 storage space both for steam and wateix A straight and converge upwardly, these sides to '45 points. "To -the'ends of the outer sh'ellare chamber-14 andanother fueldoor T18eis'llo A further objectis to provide a generator merging at their upper ends through a transwhich is economical -to operate. versely arched crown portion 7. Thus there Another object is to provide a steam generis formed between the inner and' outer shells ator utilizing both water and fire tubes which side water spaces 8 which gradually increase 10 are mounted in a simple and effective way and in width from the bottom to the top and join can be cleaned readily.- above the crown portion 7 Horizontal A further object i to provide a generator water tube 9 connect the water-legs 4 and 5 utilizing superposed grates one of which conand are supported above the lower grate 1O stitutes a water grate, the products of comand the bridge wall 11 located back of the 15 bustion from both grates being adapted to grate. These tubes 9 cooperate to form an flow together through the generator. upper or water grate. Another series of hori- Another object is to so construct the inner zontal water tubes 12 is arranged above the shell of thegenerator as to eliminate projecttubes 9, these tubes 12 being secured within ing surfaces on which scale and mud might the water-legs 4 and 5 as shown. Erected on 20 accumulate. a a the tubes 9 and extending upwardly to the With the foregoing and other objects in tubes 12 is a partition 13 which can be formed view which will appear as the description of fire brick or of a fire-resisting plastic maproceeds the invention resides in the combiterial. This partition is adapted to be shifted nation and arrangement of parts and in'the forwardly or backwardly along the tubes to 95 details of construction hereinafter described reduce or increase the size of the combustion and claimed it being understood that changes chambers 14 located between the tubes 9 and in the precise embodiment of the invention tubes 12. The top of this combustion cham- "may be made within the scope of what is ber is closed by a cover 15 of fire brick or fireclaimed without departing from the spirit of resisting plastic material laid on the tubes 12 the invention. I and preferably extending between them In the accompanying drawings the preabove the partition 13. Thus when fuel is ferred form of the invention has been shown. burning in the combustion chamber 14, the

In said drawings, products of combustion must flow downward- Figure 1 is a front elevation of a steam ly between the tubes 9 and backwardly over generator embodying the present improvethe bridge wall 11. While passing over this ment. 7 I fire wall the products of combustion will meet Figure 2 is a section on line 22, Figure 1. with those products resulting from the com- Figure 3 ma section on line 3'3, Figure 2. bustion of fuel on the grate 10. Referringto the figures by characters of For the purpose of facilitating cleaning reference 1 designate the outer shell of the and repairing the water tubes, removable generator, this shell being formed preferably screw plugs 16 are mounted in the water-legs ofsheet irono'r sheet steel shaped to provide 4 and 5 in line with the tubes; A fuel door 17 a transversely rounded top .Zforming asteam is provided in the front water-leg 5 so that dom'e provided with an outlet 3 at one or more fuel can be delivered into the combustion cated between the grate 10 and the tubes 9 within the front water-leg 5 to permit fuel to be placed in the lower combustion chamber. A clean-out door 19 may be provided in the lower portion of the water-leg 5.

That portion of the inner shell above the cover 15 and beneath the rounded top 7 of the shell constitutes a flue 20 whereby products of combustion arising between the tubes 9 and 12 back of the partition 13 will be directed forwardly into the front smoke box 21 which is mounted on the water-leg 5. Fire tubes 22 are secured at their ends in the front and rear water-legs of the generator and communicate with the smoke box 21. These tubes are located above and atthe sides of the upper portion of the inner shell 6 and the rear ends of the fire tubes open into a rear smoke box or breeching 23 which, in turn, has an outlet 2% for communication with the stack. The water level in the generator is above the fire tubes 22 but below the tops of the outer shell so that a space 25 is thus formed in the outer shell for the reception of steam generated in the device.

The inner and outer shell and the parts associated therewith can be connected by welding or riveting and are adapted to be supported on acast metal base 26 or in any other desired manner. Fuel is adapted to be burned on the grate 10 and on the water grate formed by the tubes 9 and, as before explained, the products of combustion will pass between the partition 13 and the bridge Wall 11 thence upwardly to the flue 20, smoke box 21, tubes 22, to the breeching 23. The globules of steam generated in the water at the sides and top of the inner shell 6 will escape upwardly between the fire tubes 22 into the space above the water level. The generation of steam will also be facilitated by the use of the water tubes 9 and 12 which, with the surface of the shell 6, and the fire tubes 22, presents the maximum surface for the transmission of heat to the water in the generation of steam.

Importance is attached to the fact that the inner and outer shells are provided with smooth surfaces free of projecting ledges on which mud and scale would otherwise collect. Importance is also attached to the arrangement of the removableplugs 16 whereby the water tubes can be cleaned readily. By having the movable partitions 13 the size of the upper combustion chamber 14 can be increased or reduced according to the work required of the generator.

VVhat- 1s clanned 1s i 1. A steam generator including an outer and inner shell cooperating to provide a water holding space between the sides and tops thereof, the side portions of the space increasing in width upwardly to the top por tion, a bridge wall within the lower portion of the inner shell, a lower grate in front of the bridge wall, front and rear water-legs connected to the outer and inner shells, a horizontal series of water tubes extending over the bridge wall and lower grate and opening into the water-legs said tubes constituting a water grate, a horizontal series of water tubes within the inner shell above the water grate and spaced from the top of said shell and openinginto the water-legs, a vertical transverse partition between the water-legs supported between the series of water tubes, and a cover mounted on the upper series of water tubes extending from the front waterleg to said partition and cooperating with the partition an-d the water grate to provide an upper combustion chamber, the exhaust gases from said upper combustion chamber flowing downwardly through said lower series of tubes and mixing with the gases from the lower grate, the combined gases overflowing over said bridge wall to a passage connecting with the space above said upper series of tubes,'there being an outlet from said space.

2. A steam generator including an outer and inner shell cooperating to provide a water holding space between the sides and tops thereof, the side portions of the space increasing in width upwardly to the top portion, a bridge wall within the lower portion of the inner shell, a lower grate in front of the bridge wall, front and rear water-legs connected to the outer and inner shells, a horizontal series of water tubes extending over the bridge wall and lower grate and opening into the water-legs, said tubes constituting a water grate, a horizontal series of water tubeswithin the inner shell above the water grate and opening into the water-legs, a vertical transverse partition supported between i the series of water tubes, a cover mounted on the upper series of water tubes and cooperating with the partition and the water grate to provide an upper combustion chamber, a chamber above said cover, said combustion chamber having an outlet below said water grate between the partition and the bridge wall, a smoke box outside each water-leg, longitudinal fire tubes mounted in the water space above the inner shell and opening into the smoke boxes, said tubes extending through the upper portion of the space between the shells, that portion of the inner shell above the upper combustion chamber constituting a fine for conducting products of combustion into one smoke box, there being an outlet in the other smoke box. I

3. A steam generator including an outer shell, an inner shell having upwardly con.-

verging side walls, water-legs at each end con- 

